Introduction
Starting a business in Illinois? One of the most essential steps is obtaining a Tax ID Number—also called an Employer Identification Number (EIN)—from the IRS, and possibly a state tax ID from the Illinois Department of Revenue. If you’re asking, “how do I get a tax ID number in Illinois?”, this guide explains both federal and state-level processes.
What Is a Tax ID Number?
There are two types of tax ID numbers you may need in Illinois:
- Federal Tax ID Number (EIN): Issued by the IRS for federal tax purposes.
- Illinois State Tax ID Number: Issued by the Illinois Department of Revenue (IDOR) for state-level tax obligations.
How to Get a Federal EIN in Illinois
1. Online Application (Fastest Method)
- Visit the IRS EIN Online Assistant
- Complete the form and get your EIN instantly
- No cost and available Monday to Friday
2. Apply by Mail or Fax
- Fill out Form SS-4
- Mail it to the IRS or fax it (if you’re in a rush)
- Processing takes 4–6 weeks by mail; 4–5 days by fax
How to Get an Illinois State Tax ID
If your business will collect sales tax or hire employees, you must register with IDOR:
Steps:
- Go to MyTax Illinois
- Click “Register a New Business”
- Complete the registration wizard
- Receive your Illinois Business Tax (IBT) number after approval
Who Needs a Tax ID Number in Illinois?
- LLCs, corporations, and partnerships
- Sole proprietors with employees or selling taxable goods/services
- Nonprofits, trusts, and estates
- Any business registering for sales tax or payroll tax
Final Thoughts
How do I get a tax ID number in Illinois? Start with the IRS for your EIN and then register with MyTax Illinois for your state tax ID. Both processes are free and critical for complying with tax laws.
